Good value headphone amplifier (3-400$ range)

I haven't been in touch with the latest developments and I would appreciate some input from you guys.

My past experiences with various headphones amplifiers haven't been conclusive enough for me to own one.

I auditioned a fair few but none was able to provide substantial improvements over the headphone out of my Meridian 551 integrated amplifier. That is what currently powers both my headphones and my speakers.

I'm extremely pleased with the sound quality of the Meridian, it is a superbly transparent amplifier.

But in recent times I listen to music more around the computer, than on the couch, so I'd value the commodity of having a separate device right next to my monitor.

In principle, I am looking for a headphone amplifier in the 300$ range, preferably compact in size, capable of driving inefficient AKG headphones like K501.

Alternatively I would also consider a dac/amp combination of similar pedigree, up to 400$ or so.

A dac/amp + headphones would form basically a separate setup, around my PC, so I don't need to power on the rest of my gear.

I'm not expecting a 400$ dac/amp to match or exceed the performance of the Cambridge-Meridian pair, but it would be nice if it came close.

My main concern is really about amplification. The two headphones I use the most are the K501 and the Sennheiser HD800. Both sound wonderful out of the Meridian, but I don't like them straight out of the soundcard.

The Xonar ST's sound quality itself is actually quite good, but I think the amplification is poor. It has the juice to drive the headphones, but not the quality. I tested it against the Meridian's headphone out using the Xonar's DAC and the differences were staggering. Surprisingly not on the AKG, but on the Sennheiser.

That's why I was considering an amp as an option.

From what I read so far there are a lot of interesting options out there at much more reasonable prices than I expected.

As a dac/amp I was looking at Meridian Explorer, but I'm not sure how well it can drive headphones or how loud.

Centrance Dacport is another interesting alternative, specs look very good in terms of power output and reviews are also good.

In terms of amplification alone I'm not yet in the clear and need to read more on that. I'm not sure if the Xonar ST + amp would do better than a dac/amp of similar value.

And there's also the DIY alternative, which I wouldn't mind.

I have some skills with a soldering iron and that can be a fun project to do.

Yeah. I would agree that you can definitely improve on the STX amplifier.

I used to own an STX and got an Objective 2 amp at the time. The Objective 2 was a better headphone amplifier. After that, I added on an ODAC and thought the ODAC/O2 combo to be clearly better than the STX. Have you considered the ODAC/O2 combo? Lots of discussion in this thread: http://www.head-fi.org/t/616331/o2-amp-odac